The Bible’s doctrine of covenant lies at the heart of Reformation teaching. It underpins our understanding of God, salvation, the church, and our future hope in Christ. It is among the most precious truths bound up with the gospel. And far from being some arcane and abstract theological detail, it is central to what it means to be a Christian.
Why? Because by entering into covenant with His people, God has not only bound us to Himself; He has bound Himself to us. This concept is important enough that several books on covenant embed this extraordinary truth in their titles.
And yet, we too often focus on the fact that we are bound to God in salvation—which is true—but fail to appreciate that this is true only because He has bound Himself to us as His people in the first place. Therefore, the idea of God’s binding Himself to His people is worth contemplating. Jesus told His disciples,
You did not choose me, but I chose you and appointed you that you should go and bear fruit and that your fruit should abide, so that whatever you ask the Father in my name, he may give it to you. (John 15:16)
John echoed this truth when he wrote, “In this is love, not that we loved God, but that he loved us” (1 John 4:10). But what does this have to do with the sacraments?
The Westminster Confession of Faith and Catechisms very helpfully and pastorally define the sacraments as “signs and seals of the covenant of grace” (WCF 27.1; WLC 162; WSC 92). That is, the sacraments not only signify something—depicting the glorious truth of the gospel not only visibly but tangibly—but they also solemnly seal it. They function as God’s guarantee of His promise.
There are times when something is too important for words. To merely state it verbally fails to impress on the hearer how much is at stake. So, the speaker may well put his hand on the hearer’s shoulder as he speaks to literally press home the seriousness of what is being stated. Or, for example, in a marriage service, the words exchanged in the vows made by the groom and bride are so important that they are reinforced by rings that are given and received, so that each time a spouse looks at the ring on his or her finger, they are reminded, not only of what they promised, but of the promise made by their husband or wife.
Because God has linked the words of His covenant in the gospel to the signs and seals of the sacraments, it is as though He is tangibly placing His hand on our shoulders and saying—in the midst of our personal sense of failure—“I have bound Myself to you forever!” God has solemnly pledged Himself to His people through His Son and has sealed His promise in blood.